Michiko Momoda

Full-wave analysis of optical waveguides using periodic boundary conditions

A numerical approach for three-dimensional optical waveguides using periodic boundary conditions in both transverse directions is presented. Expanding the electric and magnetic fields in a double Fourier series of complex trigonometric functions, Maxwells equations are reduced to the eigenvalue problem of a linear system for the Fourier coefficients. The solutions yield the vectorial eigenmode fields for guided and radiation modes, both propagating in forward and backward directions. The method is used to analyze the junction of a fiber to an embedded waveguides and the power transfer between two parallel embedded waveguides.

Analysis of an embedded dielectric waveguide with parabolic index distribution in the two-dimensional cross section

A Fourier series expansion method is applied to an accurate analysis of an embedded dielectric waveguide with parabolic index profile in a rectangular cross section. The case where the same waveguide has one discontinuity is also analyzed.

Propagation characteristics of a multilayered thin-film optical waveguide with a buffer layer

A mode-matching method is applied for precise numerical analysis of the propagation characteristics of a four-layer thin-film optical waveguide with a plano-convex layer, whose accurate description has been difficult so far. In the computation, the effects of the buffer layer on the dispersion relation and the field distribution for a few lower-order modes are investigated.

Numerical analysis of lamellar grating type periodic semiconductor waveguide with rectangular cross-section

Lamellar grating type semiconductor periodic waveguides with rectangular cross-section are analyzed numerically using Fourier series expansion method, and the wavelength characteristics of reflected and transmitted powers of both guided and radiation modes are investigated for several values of the groove depth and length of the grating waveguide. Then the effects of the radiation fields are made clear, and the preferred parameters for the stable propagation of the reflected dominant guided mode are recommended.